These files contain data supporting the results reported in Barrington et al. Mastcam-Z Analog Spectral Imager (MASI): A Mastcam-Z Testbed and Field Instrument. In Barrington et al., we describe the Mastcam-Z Analog Spectral Imager (MASI). Mastcam-Z is a stereoscopic, zoomable multispectral imaging system located on the Remote Sensing Mast (RSM) of the Perseverance Rover. Mastcam-Z is the first zoomable multispectral imaging system flown on a NASA spacecraft. The Mastcam-Z Analog Spectral Imager is a Mastcam-Z emulator built at Cornell University for three primary purposes: 1) to serve as a testbed for the pre-flight radiometric and geometric calibration of Mastcam-Z, 2) to characterize Mastcam-Z anomalies observed during calibration and operation, and 3) to act as a field instrument for collecting terrestrial analog multispectral data with the same resolution and spectral characteristics as Mastcam-Z images acquired on Mars. MASI is engineered using a combination of commercial off-the-shelf (COTS) components and Mastcam-Z flight spare hardware, and is calibrated using a similar set of algorithms to the flight instruments. We show that MASI produces reflectance values that are similar to Mastcam-Z laboratory and inflight values, and provide a detailed description of MASI’s hardware, software, and spectral data products.